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Flashcards in Module 7: Type I Deck (9)
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3 steps in allergic response

Allergen enters the body and causes Ab production (IgE, cytotropic Ab)

IgE binds to basophil or mast cells through CH4 domain

Upon second exposure, IgE surface Ab are cross linked, leading to degranulation of basophil/mast cells


Activation of mast cells results in (3)

Secretion of granular contents
Synthesis and secretion of lipid mediators
Synthesis and secretion of cytokines


Secretion of granular contents

Granules contain Histamine and Eosinophil chemotactic factor


Histamine causes

contraction of bronchioles, smooth muscle
Increase in capillary permeability
Increase is mucous gland secretions
Stimulation of nerve endings


Eosinophil Chemotactic Factor of Anaphylaxis

attracts eosinophils to the site


Eosinophil function (2)

Release of histamine and phospholipase D (downplays effect of histamine)


Synthesis and secretion of lipid mediators

Mast cells and basophils produce New Lipid Mediators of inflammation

-Prostaglandins cause vasodilation and increased vasc. permeability
-Leudotrienes cause increased vasc. permeability, bronchoconstriction, mucous secretions


Synthesis and secretion of cytokines

cytokines produced by mast cells (late phase reaction, 6-24hr post exposure)


Cytokines produced by mast cells (4)

Tumor necrosis factor and IL4: promote neutrophil/eosinophil rich inflammation

IL3: promotes mast cell proliferation

IL5: eosinophil activator